The present disclosure relates to a method and apparatus for controlling power consumption in a mobile communication system. Particularly, the present disclosure relates to a method and apparatus for controlling a power amplifier (PA), using signal properties and a traffic situation in a mobile communication system.
Two methods are used to reduce power consumption in a wireless signal processing unit, radio frequency unit, or RU. The first method is to reduce power consumption by increasing the efficiency of a PA in the view of maximum power, and the second method is to reduce RU power consumption by adjusting a PA bias according to a traffic situation in the field.
Since the first method is designed in the view of maximum power, the efficiency of the PA is reduced when traffic in the field is low. Hence, the first scheme is not reasonable in reducing power consumption.
The second method may be divided into two schemes. One is a PA bias on/off scheme based on a real-time downlink schedule result in a time division duplexer (TDD) Orthogonal Frequency-Division Multiple Access (OFDMA)-based wireless system. The other is a scheme in which a digital signal processing unit, digital unit, or DU receives traffic load information and increases the efficiency of a PA by adjusting a PA gate drain bias according to the received information.
In a time division duplexer (TDD) system, one frame includes a downlink (DL) subframe and an uplink (UL) subframe. A base station transmits a radio wave in the DL subframe and receives a terminal signal in the UL subframe. In an orthogonal frequency division multiple access (OFDMA)-based DL subframe resource area, a scheduling algorithm allocates resources to symbols in a way to enable maximum use of the frequency area from the first orthogonal frequency division multiplexing (OFDM) symbol. As a result, an OFDM symbol duration, to which a DL burst is not allocated, may exist. In the OFDM symbol duration, to which the burst is not allocated, power consumption may be reduced by turning off a PA bias. At this time, an operation of controlling a bias by transferring a scheduling result to an RU for each frame may be performed. However, a frequency division duplexer (FDD) system includes a control channel which cannot be controlled by the scheduling algorithm, and thus it is difficult to generate an Orthogonal Frequency Division Multiplexing (OFDM) symbol duration to which a DL burst is not allocated in FDD system.
A PA bias control method may adjust an RU PA bias voltage level during a time at which physical resource block (PRB) usage is low, thereby reducing power consumption. To this end, the method may perform a scheduling based on the limited number of resource blocks (RBs) to minimize an influence on an RU amp and coverage. In the current implemented PA bias control method, traffic monitoring is performed based on statistics. Therefore, when user traffic suddenly increases, peak throughput may be not satisfied.